Systems and methods are disclosed for modifying the hierarchy of a System-on-Chip and other circuit designs to provide better routing and performance as well as more effective power distribution. A user specifies desired modifications to the design hierarchy and then the system automatically alters the hierarchy by performing group, ungroup, and move operations to efficiently and optimally implement the desired hierarchy modifications. Any modifications to port and signal names are automatically resolved by the system and the resultant RTL matches the function of the input RTL. The user then evaluates the revised hierarchy with regard to power distribution and routing congestion, and further hierarchy modifications are performed if necessary. A widget user interface facility is included to allow user-guided direction of hierarchy modifications in an iterative fashion.